In the application of which this is a continuation-in-part, the whole of which is incorporated herein by reference, there is disclosed a mechanism for forming a heat seal and a cut transversely of a tube of flexible packaging material, the mechanism including a carrier to contact the tube, heat sealing means on the carrier to form a heat seal across the tube when contact takes place, and a resistive wire on the carrier which can be energized to cut the tube when the carrier is in contact with the tube.
In the embodiments disclosed in the earlier application, the tube of flexible packaging material is severed, transversely to its direction of movement, into a plurality of identical containers each having a main body with two opposed lower pointed corners.
In the earlier application, a heat sealing and cutting apparatus downstream of the container forming apparatus is described. This apparatus includes mechanisms to collapse each pointed lower corner of the container into a flattened triangular shape and then heat the collapsed corner to weld the corner together in the flattened condition. The mechanisms incorporate resistive cutting ribbons adapted to sever the flattened triangular corners.
This continuation-in-part application is directed to a variant in terms of dealing with the opposed pointed lower corners of the container as manufactured, in which the corners are first pinched to collapse the corners into flattened triangular shapes while adding heat in order to weld the corners together in the flattened condition, this being followed by bending each flattened corner to lie under the respective main body of the container, while the flattened corner still retains heat. It is found that this step of bending the flattened corners, while they still retain heat, is sufficient for the flattened corners to remain in position in which they lie under the main body of the container.